A pontoon bridge is a collection of specialized, shallow draft boats or floats, connected together to cross a river or canal, with a track or deck attached on top.

[2] The supporting boats or floats can be open or closed, temporary or permanent in installation, and made of rubber, metal, wood, or concrete.

Ice or floating objects (flotsam) can accumulate on the pontoons, increasing the drag from river current and potentially damaging the bridge.

The later Song dynasty (960–1279 AD) Chinese statesman Cao Cheng once wrote of early pontoon bridges in China (spelling of Chinese in Wade-Giles format): The Chhun Chhiu Hou Chuan says that in the 58th year of the Zhou King Nan (257 BC), there was invented in the Qin State the floating bridge (fou chhiao) with which to cross rivers.

Sun Yen comments that this shows that the boats were arranged in a row, like the beams (of a house) with boards laid (transversely) across them, which is just the same as the pontoon bridge of today.

There was also the rebellion of Gongsun Shu in 33 AD, where a large pontoon bridge with fortified posts was constructed across the Yangtze River, eventually broken through with ramming ships by official Han troops under Commander Cen Peng.

[18] On October 22, 1420, Ghiyasu'd-Din Naqqah, the official diarist of the embassy sent by the Timurid ruler of Persia, Mirza Shahrukh (r. 1404–1447), to the Ming dynasty of China during the reign of the Yongle Emperor (r. 1402–1424), recorded his sight and travel over a large floating pontoon bridge at Lanzhou (constructed earlier in 1372) as he crossed the Yellow River on this day.

[citation needed] During the Middle Ages, pontoons were used alongside regular boats to span rivers during campaigns, or to link communities which lacked resources to build permanent bridges.

The Ostrogothic Kingdom constructed a fortified bridge across the Tiber during the siege of Rome in 545 to block Byzantine general Belisarius' relief flotillas to the city.

The Carolingian army of Charlemagne constructed a portable pontoon bridge of anchored boats bound together and used it to cross the Danube during campaigns against the Avar Khaganate in the 790s.

[26] The German army of Otto the Great employed three pontoon bridges, made from pre-fabricated materials, to rapidly cross the Recknitz river at the Battle on the Raxa in 955 and win decisively against the Slavic Obotrites.

[27] Tenth-Century German Ottonian capitularies demanded that royal fiscal estates maintain watertight, river-fordable wagons for purposes of war.

The French Royal Army of King Philip II of France constructed a pontoon bridge across the Seine to seize Les Andelys from the English at the siege of Château Gaillard in 1203.

The French army of King Louis IX of France crossed the Charente on multiple pontoon bridges during the Battle of Taillebourg on 21 July 1242.

Louis IX had a pontoon bridge built across the Nile to provide unimpeded access to troops and supplies in early March 1250 during the Seventh Crusade.

[28][29] French general Jean Lannes's troops built a pontoon bridge to cross the Po river prior to the Battle of Montebello (1800).

Napoleon's Grande Armée made extensive use of pontoon bridges at the battles of Aspern-Essling and Wagram under the supervision of General Henri Gatien Bertrand.

Working in cold water, Eblé's Dutch engineers constructed a 100-meter-long pontoon bridge during the Battle of Berezina to allow the Grande Armée to escape to safety.

Lt Col Charles Pasley of the Royal School of Military Engineering at Chatham England developed a new form of pontoon which was adopted in 1817 by the British Army.

[33] A comparison of pontoons used by each nations army shows that almost all were open boats coming in one, two or even three pieces, mainly wood, some with canvas and rubber protection.

[31] In 1862 the Union forces commanded by Major General Ambrose Burnside were stuck on the wrong side of the Rappahannock River at the Battle of Fredericksburg for lack of the arrival of the pontoon train, resulting in severe losses.

[35] From 1864 a lightweight design known as Cumberland Pontoons, a folding boat system, were widely used during the Atlanta Campaign to transport soldiers and artillery across rivers in the South.

[5] Both types of bridges were supported by pontons (known today as "pontoons") fitted with a deck built of balk, which were square, hollow aluminum beams.

The 220 inches (560 cm) wheelbase chassis included a 25,000 pounds (11,000 kg) front winch and extra-large air-brake tanks that also served to inflate the rubber pontoons before they were placed in the water.

The system consisted of a wheeled amphibious truck equipped with inflatable outboard flotation sponsons and a rotating vehicle bridge deck section.

Operation Badr, which opened the Yom Kippur War between Egypt and Israel, involved the erection of at least 10 pontoon bridges to cross the Canal.

In 1977 the West German Bundeswehr decided to adopt the SRB with some modifications and improvements, entering service in 1979 as the Faltschwimmbrücke, or Foldable Floating Bridge (FSB).

[53] "By dawn on 4 April 2003, the 299th Engineer Company had emplaced a 185-meter long Assault Float Bridge—the first time in history that a bridge of its type was built in combat.

[55] In May 2022, Ukrainian forces repelled an attempted Russian military crossing of the Donets river, west of Sievierodonetsk in Luhansk Oblast, during the Eastern Ukraine offensive.

The U.S. state of Washington is home to some of the longest permanent floating bridges in the world, and two of these failed in part due to strong winds.